Fault indicator system for high voltage connectors

ABSTRACT

The housing of a high voltage connector has embedded therein a Ushaped yoke of low coercive magnetic material embracing the conductor in the housing and having a magnetizing winding thereon connected to external terminals. Adjacent the ends of the yoke and also embedded in the housing is a reed switch which is closed when the yoke is magnetized. It is also connected to external terminals. A reset tool has external terminals connected across a chargeable capacitor for connection to the winding terminals for magnetizing the yoke and connected to a lamp in series with a current source for connection to the external terminals of the reed switch for detecting whether it occupies a closed or an open position.

United States Patent 1 Schweitzer, Jr.

[ 51 Apr. 8, 1975 [75] Inventor: Edmund O Schweitzer, Jr.,

Northbrook, 111.

[73] Assignee: E. O. Schweitzer Mfg. Co. 1nc.,

Mundelein, 111.

221' Filed: Feb. 11,1974

211 Appl. No.: 441,298

[52] U.S. Cl. .Q 317/58; l74/D1G. 10; 324/133; 340/253 A; 340/253 A [51]Int. Cl. 02h H00 [58] Field of Search 324/51, 133, 103; 174/11 BH, DIG.10; 335/293; 317/58;

[56] References Cited UNITED STATES PATENTS 25 12/1965 Ledocq l74/DIG.1O 86 11/1970 Schweitzer 317/58 3.715.742 2/1973 Schweitzer 340/253 APrimary Examiner-James D. Trammell Attorney, Agent, or Firm-Robert R.Lockwood [57] ABSTRACT The housing of a high voltage connector hasembedded therein a U-shaped yoke of low coercive magnetic materialembracing the conductor in the housing and having a magnetizing windingthereon connected to external terminals. Adjacent the ends of the yokeand also embedded in the housing is a reed switch which is closed whenthe yoke is magnetized. It is also connected to external terminals. Areset tool has external terminals connected across a chargeablecapacitor for connection to the winding terminals for magnetizing theyoke and connected to a lamp in series with a current source forconnection to the external terminals of the reed switch for detectingwhether it occupies a closed or an open position.

8 Claims, 6 Drawing Figures 1 FAULT INDICATOR SYSTEM FOR HIGH VOLTAGECONNECTORS This invention relates. generally, to means for detectingflow of fault current in a high voltage circuit and for resetting thedetecting system. It constitutes an improvement over the systemsdisclosed in my US Pat. Nos. 3,538,386, issued Nov. 3, 1970, and3,715,742, issued Feb. 6, 1973.

Among the objects of this invention are: To provide fault responsivemeans as an integral part of a high voltage connector which comprises aninsulating housing in which a conductor and the connector elements areembedded; to provide the fault responsive means in the form of a yoke oflow coercive force magnetic material embracing the conductor and havinga magnetizing winding thereon together with a reed switch havingseparable contacts that are closed when the yoke is magnetized; to embedthe yoke with its magnetizing winding and the reed switch in theinsulating housing; to provide external terminals for the magnetizingwinding and the reed switch; to provide a fault detecting and reset toolhaving terminals for engaging the external terminals on the housing; toconnect a capacitor in the reset tool across the external terminalsthereof and to charge the capacitor from a direct current source onmanual closure of a switch for energizing the magnetizing winding; andto connect a lamp in series with the direct current source and acrossthe reed switch to determine whether it is closed or open.

In the drawings:

FIG. 1 is a view, in side elevation with a part shown in section, offault detecting connector means in which this invention is embodied.

FIG. 2 is a view, similar to FIG. 1, at a slightly reduced scale andshows in section certain details of con struction.

FIG. 3 is a view in perspective and somewhat diagrammatic in characterthat illustrates the fault detecting connector means of this invention.

FIG. 4 is a diagrammatic view ofa combination indicator and reset toolfor use in conjunction with the fault detecting connector meansillustrated in the preceeding FIGS.

FIG. 5 illustrates diagrammatically the circuit connections employed inthe combination indicator and reset tool.

FIG. 6 illustrates how remote indicating and reset means can beconnected to the fault detecting connector means.

Referring now particularly to FIGS. 1 and 2 of the drawings thereference character 10 designates, generally, fault detecting connectormeans in which this invention is embodied. It comprises a moldedinsulating I housing 11 of conventional material in which is embedhighvoltage electric power distribution system. For example it may be anunderground insulated conductor. The conductor extension 12 is connectedto a terminal 14 which may be a terminal of a transformer, such asservation. For this purpose a bifurcated yoke of low coercive material,indicated generally at 15, is embedded in the insulating housing 11 andembraces the conductor extension 12 as illustrated more clearly in FIG.3. The yoke 15 comprises U-shaped arms 16 and 17 which are connected atone end by a connection section 18. A magnetizing winding 19 extendsaround the U-shaped arms 16 and 17. On application of sufficient directcurrent to the magnetizing winding 19, the yoke 15 is magnetized and itretains this magnetism until it is demagnetized by flow of alternatingfault current in the conductor extension 12.

Across the distal ends 20 and 21 of the arms 16 and 17 is positioned areed switch that is indicated, generally, at 22. Like the yoke 15 withthe winding 19 thereon, the reed switch 22 also is embedded in thehousing 11 when it is molded. The reed switch 22 is provided with switchcontacts 23 and 24 that normally are engaged when the yoke 15 ismagnetized. They are separated when the yoke 15 is demagnetized. Thus,the position of the switch contacts 23 and 24, either open or closed,indicates whether the yoke 15 is still magnetized or has beendemagnetized as a result of flow of fault current through the conductorextension 12.

With a view to magnetizing the winding 19 from an external source andfor detecting the position of the switch contacts 23 and 24 theinsulating housing 11 is provided with a flat surface 25 in whichexternal contacts 26A and 26B are located, and shown in FIG. 3. They areconnected to the terminals of the magnetizing winding 19. Likewise inthe flat surface 25 external contacts 26C and 26D are located and, asshown in FIG. 3, they are connected, respectively, to the switchcontacts 23 and 24. It will be understood that the flat surface 25 maybe located at the bottom of a socket or other suitable locating means asmay be desired.

With a view to indicating the position of the switch contacts 23 and 24and for energizing the winding 19 there is provided a combinationindication and reset tool that is indicated, generally, at 31 .in FIG.4. In genera] the tool 31 may resemble a flashlight and may be providedwith an insulated tool housing 32 that is tubular in configuration. Apair of contacts 33 and 34 project from one end of the housing 32 whichcontains a source of direct current in the form of three flashlightbatteries 35. This particular source of direct current is referred tofor illustrative purposes. One terminal 36 of the direct current source35 is connected to the contact 34 while the other terminal 37 isconnected by a manually operable switch means 38 to signalling means 39,preferably in the form of an indicating lamp, which, in turn, isconnected to the other of the pair of contacts 33. The manually operableswitch 38 preferably is in the form of a push button. The signallingmeans 39 can also be in the form of a sonic device such as a bell orbuzzer.

For energizing the winding 19 a capacitor 43 is employed. It isconnected across the contacts 33 and 34 and is arranged to be chargedthrough the lamp 39 when the manually operable switch means 38 isclosed.

In operation, when it is desired to test the condition of the reedswitch 22, the tool 31 is manipulated to place the contacts 33 and 34 inengagement with the external contacts 26C and 26D. This is illustratedin FIG. 4. If the lamp 39 lights up, then the lineman knows that theswitch contacts 23 and 24 of the reed switch 22 are closed and that theyoke 15 is magnetized. Also this advises him that no fault current hasflowed through the conductor extension 12.

However, if the lamp 39 fails to light, then the lineman knows that theswitch contacts 23 and 24 of the reed switch 22 are open. This indicatesthat the yoke is demagnetized as a result of the flow of alternatingfault current through the conductor extension 12.

Under these circumstances it is desirable that the yoke 15 beremagnetized. For this purpose the lineman shifts the tool 31 to placethe contacts 33 and 34in engagement with the external contacts 26A and268. This is illustrated by broken lines in FIG. 4. The capacitor 43,which previously was charged through the lamp 39 on closure of themanually operable switch means 38 now discharges through the winding 19to remagnetize the yoke 15.

FIG. 6 illustrates how the winding 19 can be remagnetized from a remotepoint and also how the position of the switch contacts 23 and 24 can bedetermined from the remote point. For this purpose cable means 44 in theform of a pair of conductors is connected to the external contacts 26Aand 268. Then at a remote point a suitable source of direct current canbe provided for connection across the cable means 44 to reset the faultdetecting means. Likewise cable means 45 in the form of a pair ofconductors can be connected to the external contacts 26C and 26D andconnected across signalling means such as the lamp 39 in series with thedirect current source 35 to indicate at the remote point whether theswitch contacts 23 and 24 are closed or open.

I claim:

1. Fault detecting connector means for interconnecting a high voltagealternating current conductor and a terminal comprising: an insulatinghousing, a conductor extension in said housing for connecting saidconductor to said terminal, a yoke of low coercive magnetic materialwithin said housing and embracing said conductor extension, windingmeans on said yoke for magnetizing it, switch means adjacent said yoke,said switch means occupying one position when said yoke is magnetizedandan alternate position when said yoke is demagnetized by flow of faultcurrent through said conductor extension, terminal means exterior to andmounted on said housing, and conductor means interconnecting saidwinding means and said switch means to said terminal means.

2. Fault detecting connector means according to claim 1 wherein saidhousing is formed of moldable plastic and said yoke with said windingmeans thereon and said switch means are embedded in said housing.

3. Fault detecting connector means according to claim 1 wherein saidterminal means exterior to said housing are connected to faultindicating means and to reset means for remagnetizing the yoke.

4. Fault detecting connector means according to claim 3 wherein saidfault indicating means includes a current source and signalling meansfor connection across said switch means.

5. Fault detecting connector means according to claim 3 wherein saidresetmeans includes a direct current source and a capacitor forconnection across said winding means.

6. Fault detecting connector means according to claim 3 wherein saidfault indicating means includes a series connectable direct currentsource and a signalling device, said reset means includes a capacitorconnected to one terminal of said direct current source, and a manuallyoperable switch is arranged to connect said series connected directcurrent source and said signalling device across said switch means andto connect said capacitor to another terminal of said direct currentsource and across said winding means.

7. Fault detecting connector means according to claim 1 wherein cablemeans connect said winding means and said switch means to terminal meansremote from said housing for connection to fault indicating means and toreset means for magnetizing said yoke.

8. For combination with an insulating housing enclosing a high voltagealternating current conductor embraced by a yoke of low coercivemagnetic material having reset winding means thereon, switch meansadjacent said yoke having switch contacts operated from closed positionto open position depending upon the magnetization or demagnetization ofsaid yoke. and external contacts connected to said reset winding meansand to said switch contacts; a combination indication and reset toolcomprising an insulating tool housing having a pair of contacts forconnection to said external contacts and across either said resetwinding means or across said switch contacts of said switch means, asource of direct current in said tool housing having one terminalconnected to one of said pair of contacts, signalling means carried bysaid tool housing and connected to the other of said pair of contacts,manually operable switch means for connecting said signalling means toanother terminal of said source of direct current whereby saidsignalling means is energized when said pair of contacts engages saidexternal contacts connected to said switch contacts and said switchcontacts are closed, and capacitor means connected across said pair ofcontacts and charged when said manually operable switch means is closedwhereby said reset winding means is energized and said pair of contactsengages said external contacts connected to said reset winding means.

1. Fault detecting connector means for interconnecting a high voltagealternating current conductor and a terminal comprising: an insulatinghousing, a conductor extension in said housing for connecting saidconductor to said terminal, a yoke of low coercive magnetic materialwithin said housing and embracing said conductor extension, windingmeans on said yoke for magnetizing it, switch means adjacent said yoke,said switch means occupying one position when said yoke is magnetizedand an alternate position when said yoke is demagnetized by flow offault current through said conductor extension, terminal means exteriorto and mounted on said housing, and conductor means interconnecting saidwinding means and said switch means to said terminal means.
 2. Faultdetecting connector means according to claim 1 wherein said housing isformed of moldable plastic and said yoke with said winding means thereonand said switch means are embedded in said housing.
 3. Fault detectingconnector means according to claim 1 wherein said terminal meansexterior to said housing are connected to fault indicating means and toreset means for remagnetizing the yoke.
 4. Fault detecting connectormeans according to claim 3 wherein said fault indicating means includesa current source and signalling means for connection across said switchmeans.
 5. Fault detecting connector means according to claim 3 whereinsaid reset means includes a direct current source and a capacitor forconnection across said winding means.
 6. Fault detecting connector meansaccording to claim 3 wherein said fault indicating means includes aseries connectable direct current source and a signalling device, saidreset means includes a capacitor connected to one terminal of saiddirect current source, and a manually operable switch is arranged toconnect said series connected direct current source and said signallingdevice across said switch means and to connect said capacitor to anotherterminal of said direct current source and across said winding means. 7.Fault detecting connector means according to claim 1 wherein cable meansconnect said winding means and said switch means to terminal meansremote from said housing for connection to fault indicating means and toreset means for magnetizing said yoke.
 8. For combination with aninsulating housing enclosing a high voltage alternating currentconductor embraced by a yoke of low coercive magnetic material havingreset winding means thereon, switch means adjacent said yoke havingswitch contacts operated from closed position to open position dependingupon the magnetization or demagnetization of said yoke, and externalcontacts connected to said reset winding means and to said switchcontacts; a combination indication and reset tool comprising aninsulating tool housing having a pair of contacts for connection to saidexternal contacts and across either said reset winding means or acrosssaid switch contacts of said switch means, a source of direct current insaid tool housing having one terminal connected to one of said pair ofcontacts, signalling means carried by said tool housing and connected tothe other of said pair of contacts, manually operable switch means forconnecting said signalling means to another terminal of said source ofdirect current whereby said signalling means is energized when said pairof contacts engages said external contacts connected to said switchcontacts and said switch contacts are closed, and capacitor meansconnected across said pair of contacts and charged when said manuallyoperable switch means is closed whereby said reset winding means isenergized and said pair of contacts engages said external contactsconnected to said reset winding means.